SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c36432f10d425694529e4d6ac1f2c460c95c48aab1c6a70d0cffeeb416b1ca50' 
  AND token = 'jfEDgllGhTu20HvaMsglb/KXfTBgmxHeXCjQPnkkoJI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}