SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9306c24a64265298773ec6209e99ce68f2fbc9a692269ded08c105f7ff3fcfd4' 
  AND token = 'lf1Fvfb5L+SDizUgjCQhA+dTGT+FgcsFH1uvkqOPTF8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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