SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a88b4bb511c3676286ca77e5e45b1ad22d96ea64cd94c7f396285cffff9826c8' 
  AND token = '0X5Rx/NbbgLIyUS8+hoxYR3BZsrMAbpNFwCP0FzI6Qk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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