SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5cc826c3ccc8da073f7e61f582ef921c9230a53f5f473c516d2b42e0f8e9bfd4' 
  AND token = 'Li+2lGwMfxH+0nd0UBvlS2/OpIR7w6+9DUjjqzwvJR0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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