SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe886b73e14ad95eb72f8aa76f6aecb0c383845b5c664e99470bc3699ad34ef9' 
  AND token = 'FUDRrrkpLfOAHbRZ0uF20Qu2+wFVDLz43dw2cPPxzbk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}