Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e21c9a268f6b685d392d06a0a6cb9c4d4f1eec98eb597b0c5f4cbe2bbaf64d4c' 
  AND token = 'fllsMQ1Iup9nbhjDzra81mosgPJZ6BplRQXkoCpzxCQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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