SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a65104e2a73e75fcde94f3264c180e27711a22f6f39361878a0600907f51654' 
  AND token = 'xOd1F5CnkEknBuGoYQG9PKHXBAMWkmUzR9HAiM86oeA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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