SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1999b6083fa24c9cbc33432d5b76cbeb261e6fb89751c8cf2d67c8c6ae4b18f5' 
  AND token = 'i5KB/z3e34m0pPA/tkdrLwSWEd4aABDwPIK+FfATP5A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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