SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4885c7eca3f56fbbeca7a82863438bdf38005697f9528109162781b8314cc3db' 
  AND token = 'b/P/KT0SI375VT4HTKHSrlbkmp32TuOr86sZCslVQm4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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