SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '999044d9cf9fce0ffe9a84a6c8275beb0db6ff203ca14e11fc28430070169547' 
  AND token = 'WgujVNWc2VTdzquBWr9whxkKnC7hH7KSi8+3L/9DJoI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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