SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1321df3f724cd8dee87839b654881184aa12cc5c32b5dcd7395a8291646ac8f' 
  AND token = 'w+GQwdPsNB64bpOmPuVKEPqXBnNs+9Qd7L97oAQn7cQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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