SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f30291b25704177489c8a90c9407461f865c9f5dbc9719bc59317754d5ee4421' 
  AND token = 'kPqT0KCJXxWArFot3Ug5OpH/SBPaE7jCJkIXOKOZ8ro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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