SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64de8adba3ab12b5d5f9e4bbde1bf9e5001bdd842cc3f3dab5247925be3ae44a' 
  AND token = 's/VFelVwnkNWkmSOOg3UPetygGzxbp8//lOSPAJpDNE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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