SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ece8aac6830d980984125a43f40ddb47d06e1a085b34a828fd331657a983ae5' 
  AND token = 'hp87FDPeXa5Un9NLUsJ6LcsLh26ql+Ub/WfsPmlRurk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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