SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64b6742fe4c4dc2519898019aa7037befd9d3144db7e7ff3d96fb20fc4954db9' 
  AND token = 'ljgWTqy5ekJgYv9kmQ/ZSISZlgLtHU2OGzf4mxJ3KJ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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