SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '753a625d772b6c8a072b96fb833fc0ec520180cf2d8361aff17cb4c6e9f4eb82' 
  AND token = 'aEyFtl+pl1VPh2vIB+orR3K/kZYKKx3GrBckZ+KtRoU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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