SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe0b98f1acff967bb113a6f7f32e97cb395dedd5b71115c93d4f3846df9c4672' 
  AND token = 'IgXjJLo4mHDCeMtgDKccNFYVms3qIatHjCUN9Qz3iqw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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