SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b97c8a458145a46785ebd4fa5dc9014c16f6dccc06f6907e25042ddbecc4f6a5' 
  AND token = 'zlMJilrYqc7bhC7ELREnfDS9rZjwzCPyGeM4SL6vgxs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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