SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e55710d666d3eb2cf6bcbba5bf55cc68dad0f36464a5925d58a0f40ef86efff8' 
  AND token = 'VyOFEqFmbtUOMrTd8LMuovxO2TdusHpf8Ovzwud/9ao=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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