SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6b0b6edb4ea3ac871fea6901a49996f2a2adae6d14d9eb1196944891e6a203e' 
  AND token = 'hfKkYShLjNaBGQhoryeMzF35mmG3xHFFsECR/Vjyfys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}