SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4228b8c0c55edbde524f6c2e4c881122cd79c58eb04dbdd58fa2075eae14bbb4' 
  AND token = '2nhHZaUzspLeqZcb5z3IN/wmLVkilVgkI6fzsJSLTcM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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