SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14b67c59338ec8f72edf26484b8103c2bd2238fdd26111d6617db0644a6df961' 
  AND token = '0R+/xcaF6wu0Kow1hKxo79W6tiKiyXSqmwMT3tbpXp0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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