SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f76763b074a1f54b8b758ef089f6e3918059c18465d0e09d6ad8957ae3157c4b' 
  AND token = '/9iJuE5uT2SVWcNkLvWWxYfIxyqKUvhHq7cdPlET12g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}