SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd88ddcbcb0bc58cda9887839d39acc310d34d70c866df5e9ea94a091bf2d2317' 
  AND token = '4q5o6DFdSwh6xkGyh56y0wsDKljEHfksQCxM3g/1wFk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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