SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c36ffeac09cba1eb88878590a9b2f3a576bde66498f6d3ea54438a3104f5d23c' 
  AND token = 'VwQ0qAKtuG2mT93flkNL9vK7v2fWFqwW1kxI7Pg6RQk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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