SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e2873e9a638e034608182a0728d1edee80cfdfd09d1c2c0abf9d8380a431418' 
  AND token = 'NJRjiuu60ZtNLBk3Xuv3N962R4v0MmTdB9qgJmg0LI8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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