SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9dad97c7689957ad2b14daad03d6f23fb922494db690bca032a2b8be1660f2d' 
  AND token = 'gJISOBfX9WmgJwpsYtxwxqDwRgO5Yeb1YGlAtN4+2FI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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