SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0958ca136ec6ecebaecff168fa294542d77a438bd889f1a2a0e65ed51c3d632' 
  AND token = 'ft37bWQxqyRMM/gnIqFVz4b5SYUUUxJ8T7SgA5efryU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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