SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f5b7c26186d81562e04cc94532900f55d5e42bfa5e051425ee21846875a1f9dd' 
  AND token = 'yTjN+b++Tb74FqDWV2t278Fuo6ZDadtooteYL41J0PY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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