SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '659c1cddf354fbcbcc4ac099dea5f47813f7c2dc357d2e50ebfc91af6016b0c2' 
  AND token = 'RUBh+BAicGcPz0aA1jeHcS9RTGRGcRcAHif6UewWYF0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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