SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd75d1f38d2fd84a60b6885811a556a38712efa4ab9f9e61cce504b1b275872fd' 
  AND token = 'chfKd/cPLbvmviqwaeigGRzs4GI84PYp1I5K0/rBJLo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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