SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fac5d554a6bab7ff774e39459535437335d96f4528982c47ffbaf68df2ec06d6' 
  AND token = 'RjeNAFWlALpPHaMcxLOAgQP965jlFiicYQypZOdo79g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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