SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd4624f8960c430094a35c7f80d0fbc58810a74c431a183ad2e3d5c5350463c6' 
  AND token = 'MeK/D5H6kcPEoLzQdMl6ybC9HJgM5bcxdO3LrWIkFXk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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