SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dadbbebdc2955b9983e587af2e45601a8882c9d28f6fcf673a495445b9fa5a03' 
  AND token = 'HmL4FUwAStOpCNMiLkENf9/S4Q9aQm0xATpOPe9nGRQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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