SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a37205b76f8dc4c09dd1d545c26f280473183e6b0e179a6be9306680ffd7e591' 
  AND token = 'pOMhNEtlTQSxuzt1/bHZOp89cgDllRkV3R+bXqD2jw4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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