SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0335a6f90888869f9751ebd4c1144e92c9af7cf847899bd0086f82655bc0ed1' 
  AND token = 'POW0LilBEvE+znjnURGi47ke72cr5AwJHhurTllvJWY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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