SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de9f9da3a4e268d82509b617e711be83bd55b9fd8e572d4b839849ab965a73dd' 
  AND token = 'trx6Ix2MRevPG+/cQkBzHv4G0h90ViYqL3FylvV4V+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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