SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17277bde64234462ed5dc2ee40eab6e0b3f03e4aae460bbaeaa1b1aeace2d470' 
  AND token = 'KlhTGJSsQOy9hjJfMISwe7jNYAc6abmo3+jou/Tkzdo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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