SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f2fa648beba928607a72e720cf8b142eb16b1ce164b06b63591246a285f4654' 
  AND token = 'CDQ6vReAcLpk4hyuez1VDa6U5U7ZF/lEvJabdzkGlLA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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