SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30f662fac1a1d8fe8a17533cb0e02230891725f51d361f628665aff4ac1d83e5' 
  AND token = 'MMOvgxO+Lga+e5T/qgz2GHu+CVkDq8i2lHXNHUipq2Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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