SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4737d602a8f157accb5efc573d020499dc1e1070d01946f67f14b06825c70b18' 
  AND token = 'OGg8sqZHZFERvj4hqCHt9c9/CKsWT+Qb6D5CF+dRFKE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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