SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e1da1061bc871aad2bc445b74cc628139cb108f554ae2dd90e1996110552028' 
  AND token = 'NKpW7bWrBcW68HmZo+CyL9bhF2ANsI0AJatxzKZ71ng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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