SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1ea135321ad12288b170a8038063081c636ef5a831add735e62e425f83d4a93' 
  AND token = 'AlCdcosMYUHPFnIiRTxGnttirxylikGFqnyvz+E2P5A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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