SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d019e7861e1f18c032b299d9a823e0addf3408450b5ccf4338a52b360e707f2' 
  AND token = 'VC8nKSVFsfPP8SERHHkCEGwuGBa/dr267Q8LxtfFHT8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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