SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b410ff89451fa59fd0d0e254e6fb20dfcd8dbf6f6bfea69e4cb10aeb3eb3ba0' 
  AND token = 'd6i3/iBd8u9IVkBUfH//jrlqcabWBsyfxIR1zcRgL5I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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