SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '22754ebd36157345d20ff330bf8ef89d16a7e2d19257884a87017ebaea94a6f4' 
  AND token = 'glzXodCRp4hMe6aBQPHZQYTFDU2FbDrbr+FSyuGmIrA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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