SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58fa8a08cc6c617a2e4c98be5aaf1175f388d24ab83e678de894a090295becff' 
  AND token = 'm+/vMwDX95Hj7Y0ribU6T3eQSVjWHXFKLe3BYMYp6fE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}