SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77a2e5806aaa999e10f2d6474a8f3a30246eac4c3588aef53c6d4794b87210ff' 
  AND token = 'Sj3FRfm+ZSNEkqPZw6HkFuuU0vpGYQBMY3a9gjh68s0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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