SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b131fd27d3939b41948405d7281fc25ef2f06643f6b8f6e7563bf7bf16a2c36' 
  AND token = 'icQBXVq1OpKe7haEkEpey2LrlUZ/YjKEXJoF48Nuuek=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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