SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db6447ff1899f2b15ff40714590632c0f774c44fe5af797534f37337b0b2391a' 
  AND token = 'WB8uXkqFAvv64MrurKdVRkwY4iHV4ZY2rFJaOoCRLhc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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