SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3c2f0ed069d49337a04cb7c7d74e691f7e655fb1dac1537b740045b49fcb41a3' 
  AND token = 'J8xmsYqUgQ1Dw2xTR1tdGXtYSZWJ/0JeSNhznJ3Fw4c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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