SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e114d6389b8b156e034079e347e3db38fe264952dfa25b7dccc56ad084698f19' 
  AND token = '3LlwtxjkcKy1xP74aIvs5oTzzeMSEXYbxfJ8nrW5O/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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