SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c6c09fff34d55ef0849654f6660cbfd0b2c31a350809ce53f66bf740a4685436' 
  AND token = 'Tw30eDpWgLZtxDHNKzjAeVmbKdsH3TWvd3DgJz97Nb4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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