SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ebe5298aff3290889ce5a721c53495a51117045aa0df98ab42f0d87fcf82b62b' 
  AND token = '/wNEoSh9q3xJ3p63wW4o5Y3vvBNGB/bX/H7KudLKSLI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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