SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afdef92541b0c1e26c940a02bd9c8580adaf0d8811dffc9b53c77773d34f166b' 
  AND token = 'hrHFCpvOS6Qb2aWyveYHl+qzzvVmgzS5zcRJ6PP1Nfo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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