SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e39bccad2bbabe2e3b3a36cb36286fb43320c11acbf2a053d4180e1bb08f2c9' 
  AND token = '3Ppvjo4T4v5+nbK6KaZX1FSvqxPlmoJuXusqTGVUJLI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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