SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd4584c47deac0981f58afc074697d96f06594661619803ad3547612a97e8379' 
  AND token = 'f4tvFAfG8XzuH0NaTg+HIRp99N+nJWZPWwq7QestHiQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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