SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7eaf9d2aab6126c1674076abe546ca58b6bedbd96d132529c75dc8487952a97' 
  AND token = 'OAQ48rNWdUk9X16nC+vCL8dUMchTQ1EvXGOMZfOF7ZI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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