SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'edb893a2b39bcd0afd0a17ae4febf76702994abd25249c527fcd756b54def340' 
  AND token = 'N1Qn3foY9ECXvrj/vmsqpNX/D5RCUzpWvMggpG2SZew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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